/*
   @Copyright:LeetCode
   @Author:   tjyemail
   @Problem:  http://leetcode.com/problems/invert-binary-tree
   @Language: C++
   @Datetime: 20-01-16 15:13
   */

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */

class Solution {
public:
	TreeNode* invertTree(TreeNode* root) {
		if (root==NULL) return NULL;
		swap(root->left, root->right);
		invertTree(root->left);
		invertTree(root->right);
		return root;
	}
};
